This wouldn't bother the AI, but with human players...uncertainty is good. 

I'd like to have a Spoof ship module that makes the ship sensor'ed by the other player appear as something else. (The classical Q-Ship was essentially a merchant ship with camouflaged armament.)

So, I could set my battleship to appear as a freighter, my scout to appear as a frigate, etc as well as with appearing unarmed or heavily armed and so on. To keep it simple, perhaps when activating the spoof module for a ship, just pick a design in your list of ships to mimic. Since this is partly/mostly ECM-like, having a bunch of scouts appearing as battleships could make for lots of hilarity.

Combat and specialized or high sensor research along with short distances (perhaps adjacent only) would negate the effect as well expose that they have spoofing capability.

A fleet-wide module (like the fleet warp thing) that disguises the whole fleet could be fun especially if it also applies to the planet, starport and starbase docking areas.

Again, AI would just treat it as what it saw and act accordingly, but human players would start wondering if they were fixing to wax a bunch of freighters or had stumbled across a strong battle group.

There's no real way to bluff an opponent in the game that I can see. Poker, anyone?

(Actually you CAN bluff the AI by arming your initial ships differently than what you're researching. The AI sees what you've got and starts building defenses for that, but your later ships are armed differently so you've made the AI waste research and building effort. Would probably also work with a human opponent. Heh.)

--David